The book is based in Panem, which has 12 districts, and is governed by the capitol. The people who live in the capitol do little to nothing and are concerned only with the latest fashions and entertainment. Each district is responsible for something, whether it be mines, agriculture, seafood, energy, material goods, peacekeepers.
The Hunger Games is an annual "game" in which every year tributes from each district are picked. One boy and one girl between the ages of 12 and 18 are selected at random and are forced to fight till the death against each other until one victor stands alone. If one of your tributes from your district wins the Hunger Games, it's an honor. The district gets more food and a few luxuries. It's basically a big reality show that no one really wants to watch but is forced to until it is over.

The book has lots more twists and turns. You are going to have to read it to find out more!
Find it in YA FIC Collins, S.